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Make Your Own Digital Camera ISO Test Target
dpnow writes I run a digital photography site and came across what I thought might be an interesting story. It's about a Cornell university researcher that has reverse-engineered the design of the ISO 12233 resolution test target, used by all the best digital camera testers. These usually cost over $100 but a free pdf download of the target is available. Print it out on a good quality printer and you have your own ISO-spec test target so you can find out how good (or bad) your camera really is! "
Ummm dude... it's black and white.
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:P
If you are going to comment at least look at it first... oh wait.. this is
News for nerds... stuff people talk about without reading.
Telcos have alot of dark fibre in the States. Most people assume that's optical fibre...but it's actually moral fibre.
actually, the chances are that the crappy printer prints more accurately than what the camera can capture.
world was created 5 seconds before this post as it is.
Well, in your example, the description of Mickey Mouse IS owned by Disney. The description that the ISO specifications provide is free for anyone. The trick is actually implementing it. The commercially reproduced version costs 100 pounds, this version costs less (but may not be usable if you have a crappy printer).
It's sorta like the Bible. The actual scriptures are public domain, but the various translations--NKJV, NIV, etc--are copyrighted. I can go get the original Greek/Hebrew/Aramaic texts and translate them myself and get a result that is very close to an existing translation, and it is not illegal.
Nathan
How exact of a discription is allowed? I can describe a high resolution bitmap very accurately by writing out the color values of each pixel, but I doubt that would be permissable.
Can't anyone write anything tech without feeling the need to throw in a highly-charged buzzword?
If you read the chart's creator's web page, he didn't reverse-engineer anything. He created the chart from the published international specification. That's pretty much the opposite of reverse-engineering: engineering. That is, taking a set of specifications and producing a design that meets them.
But I guess that's not as interesting-sounding.
Since the target consists only of solid black and solid white, I don't understand what role dithering has in this. Although there are curves, I don't think it's important that they be anti-aliased.
Mostly I think this is a question of the resolution of the printer. At 800x zoom on my 100 dpi monitor I can see all the small features clearly, so I expect a 1200dpi laser would render this image just fine. At 600dpi you might miss some of the fine details.
I have seen the future, and it is inconvenient.
Steve never met a camera he didn't like.
The intro's are just rehashes of the press releases, and all the test shots are done in bright light, out doors.
For a camera to suck under those conditions, it'd have to ship from the factory with grease on the lens.
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s amples.html
a chmentid=118010&stc=1 3 1193&page=7&pp=15 a chmentid=180976&stc=1 a chmentid=221673&stc=1
Why does his "the best cameras" aka "pick of the litter" page have 10 (ten) cameras listed for each of the 12 categories? He says the "cameras are not listed in order of preference":
http://www.steves-digicams.com/best_cameras.html
I can see 2-4 choices per, but 10?
Digital camera reviews are no where near as technical and detailed as they need to be to be useful, compare this:
http://www.steves-digicams.com/2003_reviews/exs3_
with this:
http://www.rcgroups.com/forums/attachment.php?att
http://www.rcgroups.com/forums/showthread.php?t=1
http://www.rcgroups.com/forums/attachment.php?att
http://www.rcgroups.com/forums/attachment.php?att
Note the "pre-printed form letter" the one guy gets back from his warranty servicing with the check mark beside the following paragraph:
"Your camera is operating according to factory specification in all modes. The phenomenon you have experienced (an orange halo visible in the bckground after taking some pictures) is not a defect in operation of your camera. It is a function of the geometry of the lens optics. Under certain lighting conditions this effect may be noticeable. Darker backgrounds will minimize or eliminate this effect."
You can no longer find the S3 or anything like it on the market, Casio has probably quietly removed it due to huge numbers of returns and warranty servicing costs. You can only find a few on eBay, and ALL are "open return" or "used return, not tested". NONE sold by happy users.
AFAIAC, digital camera reviews are nearly worthless, no matter who is doing the review.
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Well, its no problem to use those good cameras as optical microsopes in makro-modus, but these target are supposed to shot from a fixed distance, plus they are BW only, so no resolution loss due to rasterization.
Of course a colour or general quality target wouldnt be possible with that method, but plain resolution is... (given the fact that a laser printer can do REAL 1200dpi, which resolts to a shitload more pixels per frame then even a Canon 1Ds can resolve.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?